This is a small and simple prototype of a wallet alarm. Basically this wallet displays a red LED when it is opened and a blue LED when it is closed. The circuit is simple and uses 3 resistors, 2 LED(red and blue), a breadboard and a analog home made switch with 2 wires.
The breadboard receives 5V power and the voltage passes from the first resistor to the switch first wire. The second wire of the switch is connected to analog pin 2 and functions as an input. When the voltage is lower than 1000 the blue LED turns on. This LED is connected to pin 12 and uses a less powerful resistor. When the value is higher than 1000 the red LED turns on. This one is connected to pin 13 and also uses a weak resistor.
Use a battery
Improve wire connection to stabilize voltage
Embed mechanicals more friendly